Patentable/Patents/US-11476212
US-11476212

Semiconductor contact structure having stress buffer layer formed between under bump metal layer and copper pillar

PublishedOctober 18, 2022
Assigneenot available in USPTO data we have
Inventorsnot available in USPTO data we have
Technical Abstract

Semiconductor apparatus and method for manufacturing semiconductor apparatus are provided. Semiconductor apparatus includes a semiconductor substrate having metal pads, a first passivation layer, a second passivation layer, an under bump metal layer, a stress buffer layer, a copper pillar and a solder structure. First passivation layer is formed on the semiconductor substrate and covers a portion of each metal pad, the first passivation layer has first passivation layer openings to expose a first portion of each metal pad. Second passivation layer is formed on the first passivation layer, the second passivation layer has second passivation layer openings to expose a second portion of each metal pad. Under bump metal layer is formed on the second portion of each metal pad exposed by the second passivation layer opening. Stress buffer layer is formed on the under bump metal layer, and the copper pillar is disposed on the stress buffer layer.

Patent Claims
12 claims

Legal claims defining the scope of protection, as filed with the USPTO.

2

2. The semiconductor apparatus according to claim 1, wherein the material of the under bump metal layer comprises titanium, titanium-tungsten or copper.

3

3. The semiconductor apparatus according to claim 1, further comprising a solder structure disposed on the copper pillar.

4

4. The semiconductor apparatus according to claim 1, further comprising a barrier layer disposed between the copper pillar and the stress buffer layer.

5

5. The semiconductor apparatus according to claim 4, wherein the material of the barrier layer is nickel, titanium or tantalum.

6

6. The semiconductor apparatus according to claim 1, wherein a top surface of the stress buffer layer is not higher than a top surface of the second passivation layer.

7

7. The semiconductor apparatus according to claim 1, wherein a cross-sectional area of the copper pillar is greater than or equal to a cross-sectional area of the stress buffer layer.

8

8. The semiconductor apparatus according to claim 1, wherein an area of the first passivation layer opening is greater than an area of the second passivation layer opening.

9

9. The semiconductor apparatus according to claim 1, wherein a cross-sectional area of the copper pillar is greater than the area of the first passivation layer opening and the area of the second passivation layer opening.

10

10. The semiconductor apparatus according to claim 1, wherein an area of the first passivation layer opening is smaller than an area of the second passivation layer opening.

11

11. The semiconductor apparatus according to claim 10, wherein the under bump metal layer directly contacts a portion of the first passivation layer and a portion of the second passivation layer.

12

12. The semiconductor apparatus according to claim 1, wherein the under bump metal layer is further formed on an inner wall of the second passivation layer opening, and a portion of the second passivation layer at a periphery of the second passivation layer opening.

13

13. The semiconductor apparatus according to claim 12, wherein the copper pillar further covers the portion of the second passivation layer at the periphery of the second passivation layer opening.

Classification Codes (CPC)

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Patent Metadata

Filing Date

December 16, 2020

Publication Date

October 18, 2022

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Cite as: Patentable. “Semiconductor contact structure having stress buffer layer formed between under bump metal layer and copper pillar” (US-11476212). https://patentable.app/patents/US-11476212

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